Synthesis of amine-functionalized magnetic covalent organic framework for efficient magnetic solid-phase extraction...

A novel amine-functionalized magnetic covalent organic framework Fe₃O₄@COF-NH₂, constructed from 1,3,5-tris(p-formylphenyl) benzene (TFPB) and 2,2'-dinitrobenzidine (2,2'-DNB), was rationally designed and synthesized for the first time. The resulting core-shell material, which features a facile synthesis, high stability, and tunable porosity, was employed as a highly efficient adsorbent for the magnetic solid-phase extraction (MSPE) of eleven mycotoxins from complex cereal matrices. Benefiting from its abundant active sites, the adsorbent exhibited excellent performance, driven by synergistic π-π stacking and hydrogen bonding interactions. Coupled with UPLC-MS/MS, the established method achieved a rapid and robust analysis with remarkably low limits of detection (0.02-0.10 μg/kg) and excellent recoveries (74.5%-99.5%). This work provides a powerful and practical platform for the high-throughput, sensitive, and reliable monitoring of multi-class mycotoxins, demonstrating significant advantages for food safety applications.